Schéma : The primary objective of this study is to characterize the safety of Blincyto in routine clinical practice. Blincyto effectiveness, medication errors, and utilisation; and select healthcare resource use while using Blincyto will also be described. Safety and effectiveness of Blincyto in specified subgroups of patients will also be assessed.

Study groups:
Patients initiating Blinatumomab after Country-Specific Reimbursement approval in routine clinical practice

Current primary outcome:
- Proportion of subjects with specified AEs as mentioned in description [ Time Frame: Estimated to be 100 days ]
* Neurological events
* Serious Infections
* Infusion reactions, including cytokine release syndrome
* Tumour lysis syndrome
* Capillary leak syndrome
* Elevated liver enzymes
* Febrile neutropenia and neutropenia
* Decreased immunoglobulin
* Leukoencephalopathy (including PML)
* Thromboembolic events (including DIC)
* Immunogenicity (suspected with antibody test outcome)
* Worsening of hepatic impairment in patients with hepatic impairment
- Time to onset of first specified AEs [ Time Frame: Estimated to be 100 days ]
- Summary of duration of specified AEs as detailed in the description (all events and resolved/recovered events) [ Time Frame: Estimated to be 100 days ]
* Neurological events
* Serious Infections
* Infusion reactions, including cytokine release syndrome
* Tumour lysis syndrome
* Capillary leak syndrome
* Elevated liver enzymes
* Febrile neutropenia and neutropenia
* Decreased immunoglobulin
* Leukoencephalopathy (including PML)
* Thromboembolic events (including DIC)
* Immunogenicity (suspected with antibody test outcome)
* Worsening of hepatic impairment in patients with hepatic impairment
- Proportion of Blincyto administrations with medication errors [ Time Frame: Estimated to be 100 days ], defined as an unintended failure in the drug treatment process that leads to, or has the potential to lead to, harm to the patient, identified through medical records. Types of medication errors will also be described:
* incorrect Blincyto dose administered/prepared (eg. drug concentration, device issues, treatment according to SmPC)
* does not include treatment related to dexamethasone

Current secondary outcomes:
- Proportion of subjects with AEs as detailed in the description [ Time Frame: Estimated to be 100 days ]
Incidence of all AEs collected in this study (overall, and by severity and seriousness) occurring during blinatumomab treatment and up to 30 days after completion of treatment
Incidence of specified AEs and all AEs collected in this study among patient subgroups defined by demographic and clinical factors
- Proportion of patients achieving Complete Remission overall and amongst patient sub-groups [ Time Frame: Estimated to be 100 days ]
* Proportion of patients achieving Complete Remission within 2 cycles of Blincyto treatment
* Complete remission - Defined as ≤ 5% bone marrow myeloblasts, platelets more than 100,000 cells per µL, and absolute neutrophil count > 1,000 cells per µL
- Blincyto utilisation [ Time Frame: Estimated to be 100 days ]
* Duration of Blincyto use (eg. number of completed cycles, total number of days of Blincyto administration)
* Dosing pattern (eg. proportion of patients with step-up on day 8, number of cycles initiated, frequency of bag changes)
* Proportion of patients with treatment changes (eg. interruption, discontinuation, dose reduction) as indicated by the SmPC after AEs (stratified by type of event)
- Select healthcare resource use [ Time Frame: Estimated to be 100 days ]
* Setting of bag changes (eg. in the hospital, in the outpatient clinic, or at home)
* Total number of days of inpatient Blincyto treatment
* Proportion of treatment days that were inpatient
* Incidence of hospitalization not related to infusion during the time of Blincyto treatment and up to 30 days after completion
* Length of hospital stay not related to infusion during the time of Blincyto treatment and up to 30 days after completion.
- Proportion of patients receiving allogeneic HSCT overall and amongst patient sub-groups [ Time Frame: Estimated to be 100 days ], Defined for the subset of subjects who achieved CR.
- 1-year and 100-day mortality proportion after allogeneic HSCT overall and amongst patient sub-groups [ Time Frame: Estimated to be 100 days ]. Defined for the subset of subjects who achieved CR.
- Relapse-free survival (RFS) time overall and amongst patient sub-groups [ Time Frame: Estimated to be 100 days ]
Relapse-free survival (RFS) time - defined as time from CR/CRh*/CRi until relapse (proportion of blasts in bone marrow > 5% or blasts in peripheral blood after documented CR/CRh*/CRi) or death. Defined for the subset of subjects who achieved CR.
- Overall survival (OS) time overall and amongst patient sub-groups [ Time Frame: Estimated to be 100 days ]
Overall survival (OS) time - defined as time from initiation of Blincyto until death
- Proportion of patients with MRD achieving CR/CRh*/CRi within 2 cycles of Blincyto [ Time Frame: Estimated to be 100 days ]
Overall and amongst patient sub-groups - Proportion of patients with minimal residual disease (MRD) among those who achieve CR/CRh*/CRi within two cycles of Blincyto treatment - hematologic MRD detected by polymerase chain reaction (PCR) (or flow cytometry) at a level of 1 x 10-4 or higher.
- Disease Free Survival (DFS) time [ Time Frame: Estimated to be 100 days ]
Disease Free Survival time - Defined as time from initiation of Blincyto (for MRD positive patients at initiation) until date of relapse or death
- Proportion of patients achieving CR/CRh*/CRi overall and amongst patient sub-groups [ Time Frame: Estimated to be 100 days ]
Proportion of patients achieving CR/CRh*/CRi within 2 cycles Blincyto treatment
* CR defined as ≤ 5% bone marrow blasts, platelets more than 100,000 cells per µL, and absolute neutrophil count > 1,000 cells per µL
* CRh* defined as ≤ 5% bone marrow blasts, platelets more than 50,000 cells per µL, and absolute neutrophil count > 500 cells per µL
* CRi defined as ≤ 5% bone marrow blasts and incomplete recovery of peripheral blood counts